Physics of Switching and Memory Effects in Chalcogenides

Abstract

A review of the main experimental features of switching and memory effects in chalcogenide glassy semiconductors (CGS), review and analyze of the models of these phenomena was done. An electronic-thermal model of the switching effect taking into account multiphonon tunnel ionization of negative-U centers and heating is presented. The model fits experimental current-voltage characteristics of a GeSbTe films both in ohmic and exponential regions. Also the model is in good agreement with experimental dependences of threshold voltage and threshold current on temperature and thickness. This indicates that multiphonon tunnel ionization of negative-U centers and heating is the most probable mechanism of the switching effect.